Google to Switch on Seawater-Cooled Data Center This Fall

Google plans to serve live traffic from the world’s first seawater-cooled data center in Finland in the fall of this year, according to Google’s Joe Kava. Kava plans to discuss Google’s data center efficiency innovations at the search giant’s second Data Center Efficiency Summit in Zurich, Switzerland on Tuesday.

The seawater-cooled data center is unusual even for Google, a pioneer of experimental technology, which builds its own servers, experiments with making solar thermal receivers and created a subsidiary to buy and sell energy on the wholesale electricity markets. To create the seawater-cooled data center, Google bought a former paper mill in Finland in 2009, and set out to use the building’s massive quarter-mile long seawater tunnels to push water up into the building to cool a data center. The paper mill cooled some of its previous manufacturing systems with the seawater tunnels (and other industries have been known to do this), but up until now it’s basically unheard of to use seawater for data center cooling.

The seawater system uses complex filtration systems (it’s dirty seawater after all) made out of titanium plates, which don’t corrode as fast as other materials from the salty water. But the system needs to be able to be cleaned (as it does corrode every once in a while) without it going offline, which is something Kava said Google worked hard to implement. It’s a tricky feat to clean a system while also operating it, and it’s something companies in different industries (that aren’t responsible for powering crucial websites) don’t generally have to do (even nuclear plants get shut down for weeks for cleaning).

The heat transfer units are the heart of the cooling system, and the seawater pumps into the heat transfer system, cools the data center, and then the water itself is cooled slightly before being pumped back out to sea. Google wanted the water that was pumped back out to sea to be similar in temperature to the water that entered the system, as to have as little impact as possible on the surrounding ecosystem. “It was the right thing to do,” says Kava. Google also did extensive thermal modelling to study the tides, plant life, and seasons over a 30-year-period of the surrounding coastal area, and this information determined where the water should come in and out of the system, also to have as little environmental impact as possible.

While the seawater-system has a bit of a cool-factor, it also seemed like it was a labor of love, and something that Google isn’t advocating as a standard solution for data centers for everyone. If it was a smaller scale system, it might not have been economical, said Kava, who also added that the economics do work out because the data center is of a large enough size. Beyond that, the location of the building — on the water and in the right climate — was a rather uncommon find, and could be hard to recreate in other locations.

Given the seawater data center isn’t yet serving live traffic — but is in the testing phase — Google doesn’t know the exact PUE (a widely used efficiency metric) of it yet. Kava says it will likely be in the 1.1 or 1.2 range — really good. Google will also be detailing two other energy-efficient data centers in Europe on Tuesday — one in Ireland and one in Belgium — that don’t use chillers, but use outside air and evaporative cooling.

Google has been on the forefront of data center energy efficiency design, and as Yahoo and Facebook start to show of data center efficiency designs, too, a healthy competition has emerged.